23 December 2014

A New Yorker article starts off talking about killing an awful lot of rats on New Zealand, but makes its way to discussing invasive species more generally:

he project of reshuffling the world’s flora and fauna, which began
slowly with the spread of species like the Pacific rat and sped up
thanks to the efforts of acclimatization societies, has now, with global
trade and travel, accelerated to the point that, on any given day,
something like ten thousand species are being moved around just in the
ballast water of supertankers.

The picture is of Nick Smith, NZ conservation minister, in one of the photo ops with dead rats described in the article.

Many conservation efforts around crayfish involve killing a lot of invasive crayfish. But it’s unlikely many magazine articles will be written about that.

18 December 2014

One of the stock criticisms of evolution is that new species have never been seen to be created. There are plenty of examples, and one of the more recent was the creation of a new lizard species in the lab, back in 2011. I wrote a bit about about it before. At the time, it was not given a species name.

Now, a new paper by Cole and colleagues has come out on that species, and given it a new monicker, Aspidoscelis neavesi. This is a classic taxonomic paper, really, with lots of descriptions and diagnostic criteria and locations of type speciments. It is interesting in that it grapples with the question of how to deal with hybrid lineages in a taxonomic sense, which has also been a problem with Marmorkrebs.

Carl Zimmer reports on this, and talks a bit about the taxonomic puzzles:

Aspidoscelis neavesi also raises a special puzzle, Dr. Hillis noted,
because it emerged over and over again. Dr. Baumann and his colleagues
have now successfully produced fertile hybrids of Aspidoscelis inornata
and Aspidoscelis exsanguis dozens of times from different parents. Since
each lineage comes from different parents, they could arguably be
considered separate species, not just a new one.

The introduction of non-indigenous species and associated diseases can cause declines in indigenous flora and fauna and threaten local biodiversity. The crayfish plague pathogen (Aphanomyces astaci), carried and transmitted by latent infected North American crayfish, can lead to high mortalities in indigenous European crayfish populations. Although the parthenogenetic marbled crayfish (Procambarus fallax (Hagen, 1870) forma virginalis) is common in the aquarium trade and has established wild populations in Europe, its carrier status is still unknown. This study investigated one captive and three established wild-living marbled crayfish populations for an infection with the crayfish plague pathogen applying real-time PCR. We demonstrate that captive, as well as two wild marbled crayfish populations were infected by A. astaci. Although infection status in laboratory kept specimens reached high levels, marbled crayfish showed no obviously plague-related mortality. Furthermore, sequence analysis revealed that captive crayfish carried the A. astaci genotype Pc, which has earlier been isolated from the North American red swamp crayfish (Procambarus clarkii). The results indicate that due to its positive carrier status marbled crayfish poses a greater threat to local biodiversity in Europe than considered until now.